1. Field of the Invention
The invention relates to compositions and methods useful for reducing or eliminating the amount of pathogens in meat and meat products. More specifically, it relates to the addition of lactic acid producing organisms to animal feed, animal carcasses, and meat and meat products.
2. Description of Related Art
The processing and sale of meat is a major industry in the United States and around the world. Major meat products include beef, pork, chicken, and turkey. While efforts have been made to improve the safety of meat products, significant health concerns exist due in part to the presence of bacteria and other pathogenic contaminants.
From 1995 to 2000, the United States Department of Agriculture (USDA) issued 275 recalls for meat products, amounting to about 140 million pounds of adulterated meat that was present in the consumer market. Over 90% of the recalls were due to the detected presence of the potentially dangerous E. coli strain O157:H7. This bacteria was responsible for the 1993 outbreak traced to a Jack-in-the-Box restaurant in the Seattle area, in which four children died and 700 people became ill.
Animals are often fed antibiotics at low concentrations in an attempt to maintain their health and to promote growth. One side effect of this practice has been the emergence of antibiotic resistant pathogens. Drug resistant Campylobacter and Salmonella pathogens have been detected in cattle and poultry supplies. Treatment of people infected with these organisms often require aggressive multi-drug treatments. Vancomycin resistant enterococci (VRE) have been found in European livestock. The emergence of VRE in Europe is believed to have been at least in part due to the feeding of the antibiotic avoparcin to animals. Antibiotics have also been used in aquaculture. Farmed salmon, catfish, and trout have been treated with various antibacterial agents in the water.
The ingestion of pathogens in contaminated food products can lead to illness, and in some extreme cases, to death. This is of particular concern to individuals with compromised immune systems. While cooking often reduces the levels of bacteria and other pathogens to safe levels, food products are not always sufficiently cooked.
Pathogens that cause disease in the intestinal tract are known as enteropathogens. Examples of enteropathogenic bacteria, or enterobacteria, include Staphylococcus aureus, particular strains of Escherichia coli (E. coli), and Salmonella spp. Whereas most of the hundreds of strains of E. coli are harmless and live in the intestines of animals, including humans, some strains, such as E. coli O157:H7, O111:H8, and O104:H21, produce large quantities of powerful shiga-like toxins that are closely related to or identical to the toxin produced by Shigella dysenteriae. These toxins can cause severe distress in the small intestine, often resulting in damage to the intestinal lining and resulting in extreme cases of diarrhea. E. coli O157:H7 can also cause acute hemorrhagic colitis, characterized by severe abdominal cramping and abdominal bleeding. In children, this can progress into the rare but fatal disorder called hemolytic uremic syndrome (“HUS”), characterized by renal failure and hemolytic anemia. In adults, it can progress into an ailment termed thrombotic thrombocytopenic purpura (“TTP”), which includes HUS, plus fever and neurological symptoms, and can have a mortality rate as high as fifty percent in the elderly.
Efforts have been made to improve the safety of meat products. For example, the USDA instituted the Hazard Analysis and Critical Control Point (HACCP) inspection system in 1998. The HACCP requires that meat producers conduct scientific testing of E. coli and Salmonella levels in produced meat.
Reduction of risk for illnesses due to food borne pathogens can be achieved by controlling points of potential contamination. The beef industry has recognized the need to investigate pre-harvest control of pathogens, particularly E. coli O157:H7, due to potential runoff contamination, contact with humans, and the transfer of pathogens during meat processing. In particular, undercooked or raw hamburger (ground beef) has been implicated in many documented outbreaks as containing E. coli O157:H7.
Thus, there exists a need for improved materials and methods for minimizing or preventing the occurrence of pathogens in food products. This reduction can be accomplished either while the animal is still alive by minimizing the exposure of the animal to pathogens, or after processing of the meat by preventing or minimizing contamination of the meat products. These reductions or eliminations of pathogen occurrence in meat products will better protect the health and safety of the meat eating population.